ellipse

  • Expresses the amplitudes and phases for the u and v components in terms of four ellipse parameters using Foreman’s formula

Calling Sequence

import pyTMD
umajor,uminor,uincl,uphase = pyTMD.ellipse.ellipse(u,v)

Source code

pyTMD.ellipse.ellipse(u: ndarray, v: ndarray)[source]

Expresses the amplitudes and phases for the u and v components in terms of four ellipse parameters using Foreman’s formula [1]

Parameters
u: np.ndarray

zonal current (EW)

v: np.ndarray

meridional current (NS)

Returns
umajor: np.ndarray

amplitude of the semimajor semi-axis

uminor: np.ndarray

amplitude of the semiminor semi-axis

uincl: np.ndarray

angle of inclination of the northern semimajor semi-axis

uphase: np.ndarray

phase lag of the maximum current behind the maximum tidal potential of the individual constituent

References

1

M. G. G. Foreman and R. F. Henry, “The harmonic analysis of tidal model time series,” Advances in Water Resources, 12(3), 109–120, (1989). doi: 10.1016/0309-1708(89)90017-1

pyTMD.ellipse.inverse(umajor: ndarray, uminor: ndarray, uincl: ndarray, uphase: ndarray)[source]

Calculates currents u, v using the four tidal ellipse parameters from Foreman’s formula [1]

Parameters
umajor: np.ndarray

amplitude of the semimajor semi-axis

uminor: np.ndarray

amplitude of the semiminor semi-axis

uincl: np.ndarray

angle of inclination of the northern semimajor semi-axis

uphase: np.ndarray

phase lag of the maximum current behind the maximum tidal potential of the individual constituent

Returns
u: np.ndarray

zonal current (EW)

v: np.ndarray

meridional current (NS)

References

1

M. G. G. Foreman and R. F. Henry, “The harmonic analysis of tidal model time series,” Advances in Water Resources, 12(3), 109–120, (1989). doi: 10.1016/0309-1708(89)90017-1